X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=crates%2Fhir_ty%2Fsrc%2Finfer%2Fexpr.rs;h=13f64d682521e8733ec67b6fd2edb44990f02736;hb=24255e5b3dbabe7eaec1a42668d50d96d6b1aa0f;hp=b2570b97f902eaa334fe4b38e4fc5141f1d4d07a;hpb=c5ddc35a450f15d0df0a231321d06d470f846e2c;p=rust.git diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs index b2570b97f90..13f64d68252 100644 --- a/crates/hir_ty/src/infer/expr.rs +++ b/crates/hir_ty/src/infer/expr.rs @@ -8,10 +8,10 @@ use chalk_ir::{cast::Cast, fold::Shift, Mutability, TyVariableKind}; use hir_def::{ - expr::{Array, BinaryOp, Expr, ExprId, Literal, MatchGuard, Statement, UnaryOp}, + expr::{ArithOp, Array, BinaryOp, CmpOp, Expr, ExprId, Literal, Ordering, Statement, UnaryOp}, path::{GenericArg, GenericArgs}, resolver::resolver_for_expr, - AssocContainerId, FieldId, Lookup, + FieldId, FunctionId, ItemContainerId, Lookup, }; use hir_expand::name::{name, Name}; use stdx::always; @@ -23,7 +23,7 @@ infer::coerce::CoerceMany, lower::lower_to_chalk_mutability, mapping::from_chalk, - method_resolution, op, + method_resolution, primitive::{self, UintTy}, static_lifetime, to_chalk_trait_id, traits::FnTrait, @@ -60,7 +60,7 @@ pub(super) fn infer_expr(&mut self, tgt_expr: ExprId, expected: &Expectation) -> /// Return the type after possible coercion. pub(super) fn infer_expr_coerce(&mut self, expr: ExprId, expected: &Expectation) -> Ty { let ty = self.infer_expr_inner(expr, expected); - let ty = if let Some(target) = expected.only_has_type(&mut self.table) { + if let Some(target) = expected.only_has_type(&mut self.table) { match self.coerce(Some(expr), &ty, &target) { Ok(res) => res.value, Err(_) => { @@ -74,9 +74,7 @@ pub(super) fn infer_expr_coerce(&mut self, expr: ExprId, expected: &Expectation) } } else { ty - }; - - ty + } } fn callable_sig_from_fn_trait(&mut self, ty: &Ty, num_args: usize) -> Option<(Vec, Ty)> { @@ -104,11 +102,11 @@ fn callable_sig_from_fn_trait(&mut self, ty: &Ty, num_args: usize) -> Option<(Ve let trait_env = self.trait_env.env.clone(); let obligation = InEnvironment { - goal: projection.trait_ref(self.db).cast(&Interner), + goal: projection.trait_ref(self.db).cast(Interner), environment: trait_env, }; let canonical = self.canonicalize(obligation.clone()); - if self.db.trait_solve(krate, canonical.value.cast(&Interner)).is_some() { + if self.db.trait_solve(krate, canonical.value.cast(Interner)).is_some() { self.push_obligation(obligation.goal); let return_ty = self.table.normalize_projection_ty(projection); Some((arg_tys, return_ty)) @@ -134,7 +132,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { // if let is desugared to match, so this is always simple if self.infer_expr( condition, - &Expectation::has_type(TyKind::Scalar(Scalar::Bool).intern(&Interner)), + &Expectation::has_type(TyKind::Scalar(Scalar::Bool).intern(Interner)), ); let condition_diverges = mem::replace(&mut self.diverges, Diverges::Maybe); @@ -157,6 +155,11 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { coerce.complete() } + &Expr::Let { pat, expr } => { + let input_ty = self.infer_expr(expr, &Expectation::none()); + self.infer_pat(pat, &input_ty, BindingMode::default()); + TyKind::Scalar(Scalar::Bool).intern(Interner) + } Expr::Block { statements, tail, label, id: _ } => { let old_resolver = mem::replace( &mut self.resolver, @@ -200,8 +203,8 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { let inner_ty = self.infer_expr(*body, &Expectation::none()); let impl_trait_id = crate::ImplTraitId::AsyncBlockTypeImplTrait(self.owner, *body); let opaque_ty_id = self.db.intern_impl_trait_id(impl_trait_id).into(); - TyKind::OpaqueType(opaque_ty_id, Substitution::from1(&Interner, inner_ty)) - .intern(&Interner) + TyKind::OpaqueType(opaque_ty_id, Substitution::from1(Interner, inner_ty)) + .intern(Interner) } Expr::Loop { body, label } => { self.breakables.push(BreakableContext { @@ -217,7 +220,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { self.diverges = Diverges::Maybe; ctxt.coerce.complete() } else { - TyKind::Never.intern(&Interner) + TyKind::Never.intern(Interner) } } Expr::While { condition, body, label } => { @@ -229,7 +232,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { // while let is desugared to a match loop, so this is always simple while self.infer_expr( *condition, - &Expectation::has_type(TyKind::Scalar(Scalar::Bool).intern(&Interner)), + &Expectation::has_type(TyKind::Scalar(Scalar::Bool).intern(Interner)), ); self.infer_expr(*body, &Expectation::has_type(TyBuilder::unit())); let _ctxt = self.breakables.pop().expect("breakable stack broken"); @@ -263,10 +266,9 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { // collect explicitly written argument types for arg_type in arg_types.iter() { - let arg_ty = if let Some(type_ref) = arg_type { - self.make_ty(type_ref) - } else { - self.table.new_type_var() + let arg_ty = match arg_type { + Some(type_ref) => self.make_ty(type_ref), + None => self.table.new_type_var(), }; sig_tys.push(arg_ty); } @@ -281,14 +283,14 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { num_binders: 0, sig: FnSig { abi: (), safety: chalk_ir::Safety::Safe, variadic: false }, substitution: FnSubst( - Substitution::from_iter(&Interner, sig_tys.clone()).shifted_in(&Interner), + Substitution::from_iter(Interner, sig_tys.clone()).shifted_in(Interner), ), }) - .intern(&Interner); + .intern(Interner); let closure_id = self.db.intern_closure((self.owner, tgt_expr)).into(); let closure_ty = - TyKind::Closure(closure_id, Substitution::from1(&Interner, sig_ty.clone())) - .intern(&Interner); + TyKind::Closure(closure_id, Substitution::from1(Interner, sig_ty.clone())) + .intern(Interner); // Eagerly try to relate the closure type with the expected // type, otherwise we often won't have enough information to @@ -327,10 +329,8 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { }, ); let res = derefs.by_ref().find_map(|(callee_deref_ty, _)| { - self.callable_sig( - &canonicalized.decanonicalize_ty(callee_deref_ty.value), - args.len(), - ) + let ty = &canonicalized.decanonicalize_ty(&mut self.table, callee_deref_ty); + self.callable_sig(ty, args.len()) }); let (param_tys, ret_ty): (Vec, Ty) = match res { Some(res) => { @@ -340,18 +340,32 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { None => (Vec::new(), self.err_ty()), }; self.register_obligations_for_call(&callee_ty); - self.check_call_arguments(args, ¶m_tys); + + let expected_inputs = self.expected_inputs_for_expected_output( + expected, + ret_ty.clone(), + param_tys.clone(), + ); + + self.check_call_arguments(args, &expected_inputs, ¶m_tys); self.normalize_associated_types_in(ret_ty) } Expr::MethodCall { receiver, args, method_name, generic_args } => self - .infer_method_call(tgt_expr, *receiver, args, method_name, generic_args.as_deref()), + .infer_method_call( + tgt_expr, + *receiver, + args, + method_name, + generic_args.as_deref(), + expected, + ), Expr::Match { expr, arms } => { let input_ty = self.infer_expr(*expr, &Expectation::none()); let expected = expected.adjust_for_branches(&mut self.table); let result_ty = if arms.is_empty() { - TyKind::Never.intern(&Interner) + TyKind::Never.intern(Interner) } else { match &expected { Expectation::HasType(ty) => ty.clone(), @@ -363,23 +377,14 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { let matchee_diverges = self.diverges; let mut all_arms_diverge = Diverges::Always; - for arm in arms { + for arm in arms.iter() { self.diverges = Diverges::Maybe; let _pat_ty = self.infer_pat(arm.pat, &input_ty, BindingMode::default()); - match arm.guard { - Some(MatchGuard::If { expr: guard_expr }) => { - self.infer_expr( - guard_expr, - &Expectation::has_type( - TyKind::Scalar(Scalar::Bool).intern(&Interner), - ), - ); - } - Some(MatchGuard::IfLet { expr, pat }) => { - let input_ty = self.infer_expr(expr, &Expectation::none()); - let _pat_ty = self.infer_pat(pat, &input_ty, BindingMode::default()); - } - _ => {} + if let Some(guard_expr) = arm.guard { + self.infer_expr( + guard_expr, + &Expectation::has_type(TyKind::Scalar(Scalar::Bool).intern(Interner)), + ); } let arm_ty = self.infer_expr_inner(arm.expr, &expected); @@ -396,7 +401,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { let resolver = resolver_for_expr(self.db.upcast(), self.owner, tgt_expr); self.infer_path(&resolver, p, tgt_expr.into()).unwrap_or_else(|| self.err_ty()) } - Expr::Continue { .. } => TyKind::Never.intern(&Interner), + Expr::Continue { .. } => TyKind::Never.intern(Interner), Expr::Break { expr, label } => { let mut coerce = match find_breakable(&mut self.breakables, label.as_ref()) { Some(ctxt) => { @@ -427,7 +432,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { }); }; - TyKind::Never.intern(&Interner) + TyKind::Never.intern(Interner) } Expr::Return { expr } => { if let Some(expr) = expr { @@ -436,14 +441,14 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { let unit = TyBuilder::unit(); let _ = self.coerce(Some(tgt_expr), &unit, &self.return_ty.clone()); } - TyKind::Never.intern(&Interner) + TyKind::Never.intern(Interner) } Expr::Yield { expr } => { // FIXME: track yield type for coercion if let Some(expr) = expr { self.infer_expr(*expr, &Expectation::none()); } - TyKind::Never.intern(&Interner) + TyKind::Never.intern(Interner) } Expr::RecordLit { path, fields, spread } => { let (ty, def_id) = self.resolve_variant(path.as_deref(), false); @@ -458,7 +463,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { let substs = ty .as_adt() .map(|(_, s)| s.clone()) - .unwrap_or_else(|| Substitution::empty(&Interner)); + .unwrap_or_else(|| Substitution::empty(Interner)); let field_types = def_id.map(|it| self.db.field_types(it)).unwrap_or_default(); let variant_data = def_id.map(|it| it.variant_data(self.db.upcast())); for field in fields.iter() { @@ -473,7 +478,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { } }); let field_ty = field_def.map_or(self.err_ty(), |it| { - field_types[it.local_id].clone().substitute(&Interner, &substs) + field_types[it.local_id].clone().substitute(Interner, &substs) }); self.infer_expr_coerce(field.expr, &Expectation::has_type(field_ty)); } @@ -495,22 +500,25 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { }, ); let ty = autoderef.by_ref().find_map(|(derefed_ty, _)| { - let def_db = self.db.upcast(); let module = self.resolver.module(); + let db = self.db; let is_visible = |field_id: &FieldId| { module .map(|mod_id| { - self.db.field_visibilities(field_id.parent)[field_id.local_id] - .is_visible_from(def_db, mod_id) + db.field_visibilities(field_id.parent)[field_id.local_id] + .is_visible_from(db.upcast(), mod_id) }) .unwrap_or(true) }; - match canonicalized.decanonicalize_ty(derefed_ty.value).kind(&Interner) { + match canonicalized + .decanonicalize_ty(&mut self.table, derefed_ty) + .kind(Interner) + { TyKind::Tuple(_, substs) => name.as_tuple_index().and_then(|idx| { substs - .as_slice(&Interner) + .as_slice(Interner) .get(idx) - .map(|a| a.assert_ty_ref(&Interner)) + .map(|a| a.assert_ty_ref(Interner)) .cloned() }), TyKind::Adt(AdtId(hir_def::AdtId::StructId(s)), parameters) => { @@ -521,7 +529,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { Some( self.db.field_types((*s).into())[field.local_id] .clone() - .substitute(&Interner, ¶meters), + .substitute(Interner, ¶meters), ) } else { None @@ -535,7 +543,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { Some( self.db.field_types((*u).into())[field.local_id] .clone() - .substitute(&Interner, ¶meters), + .substitute(Interner, ¶meters), ) } else { None @@ -584,7 +592,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { // FIXME: record type error - expected reference but found ptr, // which cannot be coerced } - Expectation::rvalue_hint(Ty::clone(exp_inner)) + Expectation::rvalue_hint(&mut self.table, Ty::clone(exp_inner)) } else { Expectation::none() }; @@ -593,7 +601,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { Rawness::RawPtr => TyKind::Raw(mutability, inner_ty), Rawness::Ref => TyKind::Ref(mutability, static_lifetime(), inner_ty), } - .intern(&Interner) + .intern(Interner) } Expr::Box { expr } => { let inner_ty = self.infer_expr_inner(*expr, &Expectation::none()); @@ -622,7 +630,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { }, ) { Some(derefed_ty) => { - canonicalized.decanonicalize_ty(derefed_ty.value) + canonicalized.decanonicalize_ty(&mut self.table, derefed_ty) } None => self.err_ty(), } @@ -630,7 +638,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { None => self.err_ty(), }, UnaryOp::Neg => { - match inner_ty.kind(&Interner) { + match inner_ty.kind(Interner) { // Fast path for builtins TyKind::Scalar(Scalar::Int(_) | Scalar::Uint(_) | Scalar::Float(_)) | TyKind::InferenceVar( @@ -643,7 +651,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { } } UnaryOp::Not => { - match inner_ty.kind(&Interner) { + match inner_ty.kind(Interner) { // Fast path for builtins TyKind::Scalar(Scalar::Bool | Scalar::Int(_) | Scalar::Uint(_)) | TyKind::InferenceVar(_, TyVariableKind::Integer) => inner_ty, @@ -655,33 +663,21 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { } } Expr::BinaryOp { lhs, rhs, op } => match op { - Some(op) => { - let lhs_expectation = match op { - BinaryOp::LogicOp(..) => { - Expectation::has_type(TyKind::Scalar(Scalar::Bool).intern(&Interner)) - } - _ => Expectation::none(), - }; - let lhs_ty = self.infer_expr(*lhs, &lhs_expectation); - let lhs_ty = self.resolve_ty_shallow(&lhs_ty); - let rhs_expectation = op::binary_op_rhs_expectation(*op, lhs_ty.clone()); - let rhs_ty = self.infer_expr(*rhs, &Expectation::has_type(rhs_expectation)); - let rhs_ty = self.resolve_ty_shallow(&rhs_ty); - - let ret = op::binary_op_return_ty(*op, lhs_ty.clone(), rhs_ty.clone()); - - if ret.is_unknown() { - cov_mark::hit!(infer_expr_inner_binary_operator_overload); - - self.resolve_associated_type_with_params( - lhs_ty, - self.resolve_binary_op_output(op), - &[rhs_ty], - ) - } else { - ret - } + Some(BinaryOp::Assignment { op: None }) => { + let lhs_ty = self.infer_expr(*lhs, &Expectation::none()); + self.infer_expr_coerce(*rhs, &Expectation::has_type(lhs_ty)); + self.result.standard_types.unit.clone() + } + Some(BinaryOp::LogicOp(_)) => { + let bool_ty = self.result.standard_types.bool_.clone(); + self.infer_expr_coerce(*lhs, &Expectation::HasType(bool_ty.clone())); + let lhs_diverges = self.diverges; + self.infer_expr_coerce(*rhs, &Expectation::HasType(bool_ty.clone())); + // Depending on the LHS' value, the RHS can never execute. + self.diverges = lhs_diverges; + bool_ty } + Some(op) => self.infer_overloadable_binop(*lhs, *op, *rhs, tgt_expr), _ => self.err_ty(), }, Expr::Range { lhs, rhs, range_type } => { @@ -737,8 +733,9 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { krate, index_trait, ); - let self_ty = - self_ty.map_or(self.err_ty(), |t| canonicalized.decanonicalize_ty(t.value)); + let self_ty = self_ty.map_or(self.err_ty(), |t| { + canonicalized.decanonicalize_ty(&mut self.table, t) + }); self.resolve_associated_type_with_params( self_ty, self.resolve_ops_index_output(), @@ -752,11 +749,11 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { let mut tys = match expected .only_has_type(&mut self.table) .as_ref() - .map(|t| t.kind(&Interner)) + .map(|t| t.kind(Interner)) { Some(TyKind::Tuple(_, substs)) => substs - .iter(&Interner) - .map(|a| a.assert_ty_ref(&Interner).clone()) + .iter(Interner) + .map(|a| a.assert_ty_ref(Interner).clone()) .chain(repeat_with(|| self.table.new_type_var())) .take(exprs.len()) .collect::>(), @@ -767,11 +764,11 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { self.infer_expr_coerce(*expr, &Expectation::has_type(ty.clone())); } - TyKind::Tuple(tys.len(), Substitution::from_iter(&Interner, tys)).intern(&Interner) + TyKind::Tuple(tys.len(), Substitution::from_iter(Interner, tys)).intern(Interner) } Expr::Array(array) => { let elem_ty = - match expected.to_option(&mut self.table).as_ref().map(|t| t.kind(&Interner)) { + match expected.to_option(&mut self.table).as_ref().map(|t| t.kind(Interner)) { Some(TyKind::Array(st, _) | TyKind::Slice(st)) => st.clone(), _ => self.table.new_type_var(), }; @@ -791,50 +788,57 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { self.infer_expr( repeat, &Expectation::has_type( - TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(&Interner), + TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(Interner), ), ); - let repeat_expr = &self.body.exprs[repeat]; - consteval::eval_usize(repeat_expr) + consteval::eval_usize( + repeat, + consteval::ConstEvalCtx { + exprs: &body.exprs, + pats: &body.pats, + local_data: Default::default(), + infer: &mut |x| self.infer_expr(x, &expected), + }, + ) } }; - TyKind::Array(coerce.complete(), consteval::usize_const(len)).intern(&Interner) + TyKind::Array(coerce.complete(), consteval::usize_const(len)).intern(Interner) } Expr::Literal(lit) => match lit { - Literal::Bool(..) => TyKind::Scalar(Scalar::Bool).intern(&Interner), + Literal::Bool(..) => TyKind::Scalar(Scalar::Bool).intern(Interner), Literal::String(..) => { - TyKind::Ref(Mutability::Not, static_lifetime(), TyKind::Str.intern(&Interner)) - .intern(&Interner) + TyKind::Ref(Mutability::Not, static_lifetime(), TyKind::Str.intern(Interner)) + .intern(Interner) } Literal::ByteString(bs) => { - let byte_type = TyKind::Scalar(Scalar::Uint(UintTy::U8)).intern(&Interner); + let byte_type = TyKind::Scalar(Scalar::Uint(UintTy::U8)).intern(Interner); let len = consteval::usize_const(Some(bs.len() as u64)); - let array_type = TyKind::Array(byte_type, len).intern(&Interner); - TyKind::Ref(Mutability::Not, static_lifetime(), array_type).intern(&Interner) + let array_type = TyKind::Array(byte_type, len).intern(Interner); + TyKind::Ref(Mutability::Not, static_lifetime(), array_type).intern(Interner) } - Literal::Char(..) => TyKind::Scalar(Scalar::Char).intern(&Interner), + Literal::Char(..) => TyKind::Scalar(Scalar::Char).intern(Interner), Literal::Int(_v, ty) => match ty { Some(int_ty) => { TyKind::Scalar(Scalar::Int(primitive::int_ty_from_builtin(*int_ty))) - .intern(&Interner) + .intern(Interner) } None => self.table.new_integer_var(), }, Literal::Uint(_v, ty) => match ty { Some(int_ty) => { TyKind::Scalar(Scalar::Uint(primitive::uint_ty_from_builtin(*int_ty))) - .intern(&Interner) + .intern(Interner) } None => self.table.new_integer_var(), }, Literal::Float(_v, ty) => match ty { Some(float_ty) => { TyKind::Scalar(Scalar::Float(primitive::float_ty_from_builtin(*float_ty))) - .intern(&Interner) + .intern(Interner) } None => self.table.new_float_var(), }, @@ -847,6 +851,60 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { ty } + fn infer_overloadable_binop( + &mut self, + lhs: ExprId, + op: BinaryOp, + rhs: ExprId, + tgt_expr: ExprId, + ) -> Ty { + let lhs_expectation = Expectation::none(); + let lhs_ty = self.infer_expr(lhs, &lhs_expectation); + let rhs_ty = self.table.new_type_var(); + + let func = self.resolve_binop_method(op); + let func = match func { + Some(func) => func, + None => { + let rhs_ty = self.builtin_binary_op_rhs_expectation(op, lhs_ty.clone()); + let rhs_ty = self.infer_expr_coerce(rhs, &Expectation::from_option(rhs_ty)); + return self + .builtin_binary_op_return_ty(op, lhs_ty, rhs_ty) + .unwrap_or_else(|| self.err_ty()); + } + }; + + let subst = TyBuilder::subst_for_def(self.db, func) + .push(lhs_ty.clone()) + .push(rhs_ty.clone()) + .build(); + self.write_method_resolution(tgt_expr, func, subst.clone()); + + let method_ty = self.db.value_ty(func.into()).substitute(Interner, &subst); + self.register_obligations_for_call(&method_ty); + + self.infer_expr_coerce(rhs, &Expectation::has_type(rhs_ty.clone())); + + let ret_ty = match method_ty.callable_sig(self.db) { + Some(sig) => sig.ret().clone(), + None => self.err_ty(), + }; + + let ret_ty = self.normalize_associated_types_in(ret_ty); + + // FIXME: record autoref adjustments + + // use knowledge of built-in binary ops, which can sometimes help inference + if let Some(builtin_rhs) = self.builtin_binary_op_rhs_expectation(op, lhs_ty.clone()) { + self.unify(&builtin_rhs, &rhs_ty); + } + if let Some(builtin_ret) = self.builtin_binary_op_return_ty(op, lhs_ty, rhs_ty) { + self.unify(&builtin_ret, &ret_ty); + } + + ret_ty + } + fn infer_block( &mut self, expr: ExprId, @@ -856,7 +914,7 @@ fn infer_block( ) -> Ty { for stmt in statements { match stmt { - Statement::Let { pat, type_ref, initializer } => { + Statement::Let { pat, type_ref, initializer, else_branch } => { let decl_ty = type_ref .as_ref() .map(|tr| self.make_ty(tr)) @@ -873,6 +931,13 @@ fn infer_block( } } + if let Some(expr) = else_branch { + self.infer_expr_coerce( + *expr, + &Expectation::has_type(Ty::new(Interner, TyKind::Never)), + ); + } + self.infer_pat(*pat, &ty, BindingMode::default()); } Statement::Expr { expr, .. } => { @@ -881,7 +946,7 @@ fn infer_block( } } - let ty = if let Some(expr) = tail { + if let Some(expr) = tail { self.infer_expr_coerce(expr, expected) } else { // Citing rustc: if there is no explicit tail expression, @@ -900,8 +965,7 @@ fn infer_block( } TyBuilder::unit() } - }; - ty + } } fn infer_method_call( @@ -911,6 +975,7 @@ fn infer_method_call( args: &[ExprId], method_name: &Name, generic_args: Option<&GenericArgs>, + expected: &Expectation, ) -> Ty { let receiver_ty = self.infer_expr(receiver, &Expectation::none()); let canonicalized_receiver = self.canonicalize(receiver_ty.clone()); @@ -924,13 +989,13 @@ fn infer_method_call( self.trait_env.clone(), krate, &traits_in_scope, - self.resolver.module(), + self.resolver.module().into(), method_name, ) }); let (receiver_ty, method_ty, substs) = match resolved { Some((ty, func)) => { - let ty = canonicalized_receiver.decanonicalize_ty(ty); + let ty = canonicalized_receiver.decanonicalize_ty(&mut self.table, ty); let generics = generics(self.db.upcast(), func.into()); let substs = self.substs_for_method_call(generics, generic_args, &ty); self.write_method_resolution(tgt_expr, func, substs.clone()); @@ -938,13 +1003,13 @@ fn infer_method_call( } None => ( receiver_ty, - Binders::empty(&Interner, self.err_ty()), - Substitution::empty(&Interner), + Binders::empty(Interner, self.err_ty()), + Substitution::empty(Interner), ), }; - let method_ty = method_ty.substitute(&Interner, &substs); + let method_ty = method_ty.substitute(Interner, &substs); self.register_obligations_for_call(&method_ty); - let (expected_receiver_ty, param_tys, ret_ty) = match method_ty.callable_sig(self.db) { + let (formal_receiver_ty, param_tys, ret_ty) = match method_ty.callable_sig(self.db) { Some(sig) => { if !sig.params().is_empty() { (sig.params()[0].clone(), sig.params()[1..].to_vec(), sig.ret().clone()) @@ -954,13 +1019,43 @@ fn infer_method_call( } None => (self.err_ty(), Vec::new(), self.err_ty()), }; - self.unify(&expected_receiver_ty, &receiver_ty); + self.unify(&formal_receiver_ty, &receiver_ty); + + let expected_inputs = + self.expected_inputs_for_expected_output(expected, ret_ty.clone(), param_tys.clone()); - self.check_call_arguments(args, ¶m_tys); + self.check_call_arguments(args, &expected_inputs, ¶m_tys); self.normalize_associated_types_in(ret_ty) } - fn check_call_arguments(&mut self, args: &[ExprId], param_tys: &[Ty]) { + fn expected_inputs_for_expected_output( + &mut self, + expected_output: &Expectation, + output: Ty, + inputs: Vec, + ) -> Vec { + if let Some(expected_ty) = expected_output.to_option(&mut self.table) { + self.table.fudge_inference(|table| { + if table.try_unify(&expected_ty, &output).is_ok() { + table.resolve_with_fallback(inputs, &|var, kind, _, _| match kind { + chalk_ir::VariableKind::Ty(tk) => var.to_ty(Interner, tk).cast(Interner), + chalk_ir::VariableKind::Lifetime => { + var.to_lifetime(Interner).cast(Interner) + } + chalk_ir::VariableKind::Const(ty) => { + var.to_const(Interner, ty).cast(Interner) + } + }) + } else { + Vec::new() + } + }) + } else { + Vec::new() + } + } + + fn check_call_arguments(&mut self, args: &[ExprId], expected_inputs: &[Ty], param_tys: &[Ty]) { // Quoting https://github.com/rust-lang/rust/blob/6ef275e6c3cb1384ec78128eceeb4963ff788dca/src/librustc_typeck/check/mod.rs#L3325 -- // We do this in a pretty awful way: first we type-check any arguments // that are not closures, then we type-check the closures. This is so @@ -968,14 +1063,45 @@ fn check_call_arguments(&mut self, args: &[ExprId], param_tys: &[Ty]) { // type-check the functions. This isn't really the right way to do this. for &check_closures in &[false, true] { let param_iter = param_tys.iter().cloned().chain(repeat(self.err_ty())); - for (&arg, param_ty) in args.iter().zip(param_iter) { + let expected_iter = expected_inputs + .iter() + .cloned() + .chain(param_iter.clone().skip(expected_inputs.len())); + for ((&arg, param_ty), expected_ty) in args.iter().zip(param_iter).zip(expected_iter) { let is_closure = matches!(&self.body[arg], Expr::Lambda { .. }); if is_closure != check_closures { continue; } + // the difference between param_ty and expected here is that + // expected is the parameter when the expected *return* type is + // taken into account. So in `let _: &[i32] = identity(&[1, 2])` + // the expected type is already `&[i32]`, whereas param_ty is + // still an unbound type variable. We don't always want to force + // the parameter to coerce to the expected type (for example in + // `coerce_unsize_expected_type_4`). let param_ty = self.normalize_associated_types_in(param_ty); - self.infer_expr_coerce(arg, &Expectation::has_type(param_ty.clone())); + let expected = Expectation::rvalue_hint(&mut self.table, expected_ty); + // infer with the expected type we have... + let ty = self.infer_expr_inner(arg, &expected); + + // then coerce to either the expected type or just the formal parameter type + let coercion_target = if let Some(ty) = expected.only_has_type(&mut self.table) { + // if we are coercing to the expectation, unify with the + // formal parameter type to connect everything + self.unify(&ty, ¶m_ty); + ty + } else { + param_ty + }; + if !coercion_target.is_unknown() { + if self.coerce(Some(arg), &ty, &coercion_target).is_err() { + self.result.type_mismatches.insert( + arg.into(), + TypeMismatch { expected: coercion_target, actual: ty.clone() }, + ); + } + } } } } @@ -1022,27 +1148,26 @@ fn substs_for_method_call( substs.push(self.table.new_type_var()); } assert_eq!(substs.len(), total_len); - Substitution::from_iter(&Interner, substs) + Substitution::from_iter(Interner, substs) } fn register_obligations_for_call(&mut self, callable_ty: &Ty) { let callable_ty = self.resolve_ty_shallow(callable_ty); - if let TyKind::FnDef(fn_def, parameters) = callable_ty.kind(&Interner) { + if let TyKind::FnDef(fn_def, parameters) = callable_ty.kind(Interner) { let def: CallableDefId = from_chalk(self.db, *fn_def); let generic_predicates = self.db.generic_predicates(def.into()); for predicate in generic_predicates.iter() { let (predicate, binders) = predicate .clone() - .substitute(&Interner, parameters) + .substitute(Interner, parameters) .into_value_and_skipped_binders(); - always!(binders.len(&Interner) == 0); // quantified where clauses not yet handled - self.push_obligation(predicate.cast(&Interner)); + always!(binders.len(Interner) == 0); // quantified where clauses not yet handled + self.push_obligation(predicate.cast(Interner)); } // add obligation for trait implementation, if this is a trait method match def { CallableDefId::FunctionId(f) => { - if let AssocContainerId::TraitId(trait_) = f.lookup(self.db.upcast()).container - { + if let ItemContainerId::TraitId(trait_) = f.lookup(self.db.upcast()).container { // construct a TraitRef let substs = crate::subst_prefix( &*parameters, @@ -1050,7 +1175,7 @@ fn register_obligations_for_call(&mut self, callable_ty: &Ty) { ); self.push_obligation( TraitRef { trait_id: to_chalk_trait_id(trait_), substitution: substs } - .cast(&Interner), + .cast(Interner), ); } } @@ -1058,4 +1183,143 @@ fn register_obligations_for_call(&mut self, callable_ty: &Ty) { } } } + + fn builtin_binary_op_return_ty(&mut self, op: BinaryOp, lhs_ty: Ty, rhs_ty: Ty) -> Option { + let lhs_ty = self.resolve_ty_shallow(&lhs_ty); + let rhs_ty = self.resolve_ty_shallow(&rhs_ty); + match op { + BinaryOp::LogicOp(_) | BinaryOp::CmpOp(_) => { + Some(TyKind::Scalar(Scalar::Bool).intern(Interner)) + } + BinaryOp::Assignment { .. } => Some(TyBuilder::unit()), + BinaryOp::ArithOp(ArithOp::Shl | ArithOp::Shr) => { + // all integer combinations are valid here + if matches!( + lhs_ty.kind(Interner), + TyKind::Scalar(Scalar::Int(_) | Scalar::Uint(_)) + | TyKind::InferenceVar(_, TyVariableKind::Integer) + ) && matches!( + rhs_ty.kind(Interner), + TyKind::Scalar(Scalar::Int(_) | Scalar::Uint(_)) + | TyKind::InferenceVar(_, TyVariableKind::Integer) + ) { + Some(lhs_ty) + } else { + None + } + } + BinaryOp::ArithOp(_) => match (lhs_ty.kind(Interner), rhs_ty.kind(Interner)) { + // (int, int) | (uint, uint) | (float, float) + (TyKind::Scalar(Scalar::Int(_)), TyKind::Scalar(Scalar::Int(_))) + | (TyKind::Scalar(Scalar::Uint(_)), TyKind::Scalar(Scalar::Uint(_))) + | (TyKind::Scalar(Scalar::Float(_)), TyKind::Scalar(Scalar::Float(_))) => { + Some(rhs_ty) + } + // ({int}, int) | ({int}, uint) + ( + TyKind::InferenceVar(_, TyVariableKind::Integer), + TyKind::Scalar(Scalar::Int(_) | Scalar::Uint(_)), + ) => Some(rhs_ty), + // (int, {int}) | (uint, {int}) + ( + TyKind::Scalar(Scalar::Int(_) | Scalar::Uint(_)), + TyKind::InferenceVar(_, TyVariableKind::Integer), + ) => Some(lhs_ty), + // ({float} | float) + ( + TyKind::InferenceVar(_, TyVariableKind::Float), + TyKind::Scalar(Scalar::Float(_)), + ) => Some(rhs_ty), + // (float, {float}) + ( + TyKind::Scalar(Scalar::Float(_)), + TyKind::InferenceVar(_, TyVariableKind::Float), + ) => Some(lhs_ty), + // ({int}, {int}) | ({float}, {float}) + ( + TyKind::InferenceVar(_, TyVariableKind::Integer), + TyKind::InferenceVar(_, TyVariableKind::Integer), + ) + | ( + TyKind::InferenceVar(_, TyVariableKind::Float), + TyKind::InferenceVar(_, TyVariableKind::Float), + ) => Some(rhs_ty), + _ => None, + }, + } + } + + fn builtin_binary_op_rhs_expectation(&mut self, op: BinaryOp, lhs_ty: Ty) -> Option { + Some(match op { + BinaryOp::LogicOp(..) => TyKind::Scalar(Scalar::Bool).intern(Interner), + BinaryOp::Assignment { op: None } => lhs_ty, + BinaryOp::CmpOp(CmpOp::Eq { .. }) => match self + .resolve_ty_shallow(&lhs_ty) + .kind(Interner) + { + TyKind::Scalar(_) | TyKind::Str => lhs_ty, + TyKind::InferenceVar(_, TyVariableKind::Integer | TyVariableKind::Float) => lhs_ty, + _ => return None, + }, + BinaryOp::ArithOp(ArithOp::Shl | ArithOp::Shr) => return None, + BinaryOp::CmpOp(CmpOp::Ord { .. }) + | BinaryOp::Assignment { op: Some(_) } + | BinaryOp::ArithOp(_) => match self.resolve_ty_shallow(&lhs_ty).kind(Interner) { + TyKind::Scalar(Scalar::Int(_) | Scalar::Uint(_) | Scalar::Float(_)) => lhs_ty, + TyKind::InferenceVar(_, TyVariableKind::Integer | TyVariableKind::Float) => lhs_ty, + _ => return None, + }, + }) + } + + fn resolve_binop_method(&self, op: BinaryOp) -> Option { + let (name, lang_item) = match op { + BinaryOp::LogicOp(_) => return None, + BinaryOp::ArithOp(aop) => match aop { + ArithOp::Add => (name!(add), name!(add)), + ArithOp::Mul => (name!(mul), name!(mul)), + ArithOp::Sub => (name!(sub), name!(sub)), + ArithOp::Div => (name!(div), name!(div)), + ArithOp::Rem => (name!(rem), name!(rem)), + ArithOp::Shl => (name!(shl), name!(shl)), + ArithOp::Shr => (name!(shr), name!(shr)), + ArithOp::BitXor => (name!(bitxor), name!(bitxor)), + ArithOp::BitOr => (name!(bitor), name!(bitor)), + ArithOp::BitAnd => (name!(bitand), name!(bitand)), + }, + BinaryOp::Assignment { op: Some(aop) } => match aop { + ArithOp::Add => (name!(add_assign), name!(add_assign)), + ArithOp::Mul => (name!(mul_assign), name!(mul_assign)), + ArithOp::Sub => (name!(sub_assign), name!(sub_assign)), + ArithOp::Div => (name!(div_assign), name!(div_assign)), + ArithOp::Rem => (name!(rem_assign), name!(rem_assign)), + ArithOp::Shl => (name!(shl_assign), name!(shl_assign)), + ArithOp::Shr => (name!(shr_assign), name!(shr_assign)), + ArithOp::BitXor => (name!(bitxor_assign), name!(bitxor_assign)), + ArithOp::BitOr => (name!(bitor_assign), name!(bitor_assign)), + ArithOp::BitAnd => (name!(bitand_assign), name!(bitand_assign)), + }, + BinaryOp::CmpOp(cop) => match cop { + CmpOp::Eq { negated: false } => (name!(eq), name!(eq)), + CmpOp::Eq { negated: true } => (name!(ne), name!(eq)), + CmpOp::Ord { ordering: Ordering::Less, strict: false } => { + (name!(le), name!(partial_ord)) + } + CmpOp::Ord { ordering: Ordering::Less, strict: true } => { + (name!(lt), name!(partial_ord)) + } + CmpOp::Ord { ordering: Ordering::Greater, strict: false } => { + (name!(ge), name!(partial_ord)) + } + CmpOp::Ord { ordering: Ordering::Greater, strict: true } => { + (name!(gt), name!(partial_ord)) + } + }, + BinaryOp::Assignment { op: None } => return None, + }; + + let trait_ = self.resolve_lang_item(lang_item)?.as_trait()?; + + self.db.trait_data(trait_).method_by_name(&name) + } }